Browse Forums Heating, Cooling & Insulation 1 Jul 17, 2016 11:51 pm Hi I'm trying to build an eco friendly/efficient house on my little budget and basically what it boils down to is I've never really lived in a properly insulated house, so I really don't know what my heating and cooling needs will be... I've done my best to use passive solar design principles, on the plan below north is more or less up, and the main living areas will be a charcoal coloured porcelain tile, double glazed windows, R5.1 insulation to roof and R2.5 I think to the walls. Ceiling fans throughout. I'm building in south east Melbourne. I've been looking at a ducted reverse cycle split system for heating and cooling, and I'll offset some of the electricity with solar panels. But, will I definitely need it? I'm assuming I'll definitely need heating of some description, but is this the best way to do it? Will I need the aircon, or will I be ok with just fans, or maybe something like a whole house fan? Would it be a terrible idea to move in without heating and cooling and just live in the house for a while and see what I need? Is that likely to increase my install costs by much? Sorry for all the questions and thanks in advance for any insights you can give me Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Install heating/cooling during build or wait and see? 4Jul 18, 2016 7:57 am It could be worth trying, and you may not need full airconditioning. We currently live in an East Facing apartment in Melbourne and the only heating we use is a reverse cycle unit in the lounge/diner. The only additional cooling is a portable fan in the bedroom. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Install heating/cooling during build or wait and see? 5Jul 18, 2016 10:03 am bashworth It could be worth trying, and you may not need full airconditioning. We currently live in an East Facing apartment in Melbourne and the only heating we use is a reverse cycle unit in the lounge/diner. The only additional cooling is a portable fan in the bedroom. Wow Bashworth, so there's a chance I might not need it? That would be amazing, there's so much electricity to be saved there Is there anything else I could do in terms of build features to improve my comfort levels do you think? Re: Install heating/cooling during build or wait and see? 6Jul 18, 2016 10:05 am Joker I had aircon heating done once 6 months after moving in and once during build, it didn't seem to effect pricing either way. Thanks Joker, good to know Re: Install heating/cooling during build or wait and see? 7Jul 18, 2016 6:54 pm Justalittlebithippy bashworth It could be worth trying, and you may not need full airconditioning. We currently live in an East Facing apartment in Melbourne and the only heating we use is a reverse cycle unit in the lounge/diner. The only additional cooling is a portable fan in the bedroom. Wow Bashworth, so there's a chance I might not need it? That would be amazing, there's so much electricity to be saved there Is there anything else I could do in terms of build features to improve my comfort levels do you think? Some protection for the Front (west facing windows) Check out this post: http://anewhouse.com.au/2012/02/shading ... g-windows/ Point No 1 is a minimum in my opinion. Also make sure you have good insulation between the garage and the internal rooms. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Install heating/cooling during build or wait and see? 8Jul 18, 2016 10:16 pm Cheers bashworth, was planning on the insulation between the garage and at the least a small tree/large bush in front of the west window, and was definitely contemplating a film to the front windows as well. Glad to know I'm on the right track Re: Install heating/cooling during build or wait and see? 9Jul 23, 2016 3:41 pm Yay, an eco friendly "passive solar" house. Good on you, I wish there was more of them Modern reverse cycle air conditioners are very efficient heaters, between 3 & 5 times more efficient than other electric heat sources. This makes them the most economical heating option for much of Australia. But for Victoria, where natural gas is cheaper than in other states, it's not so clear cut (I haven't done the calculations, but economically I think it's much of a muchness). As you're thinking green, I'd recommend reverse AC over other heat sources. I'd actually skip any thoughts of a gas connection at all, & have an ALL ELECTRIC house. Better for the environment, plus you won't be paying those charges just to be connected to gas. Reverse AC for heating, induction cooktop (which are much better than other electric stove tops) & electric domestic hot water. For electric domestic water you can choose between a heat pump (the same type of technology as RC air con & fridges), or a simple electric element. Again, the heat pump is much more efficient, but much more costly. Economically, if you have the roof space for it, it sounds like getting an electric element, & investing the extra cash in solar panels seems to be the way to go. As for AC, you said "ducted reverse cycle split system". I'm no expert, but I don't think you can have a ducted split system, I think it's either "ducted" or "split". Split systems are more efficient than ducted systems (due to energy losses in the ducts). A split system would also have to be much much easier to install post build than a ducted system I'd expect. Particularly if your split system is a back-to-back install, where the indoor & outdoor units are just on opposite sides of a wall. If your split system is more complicated, with longer pipe runs, it may be more complicated, & more costly, to install it post build. So I'd be doing some planning, as to where you want the indoor unit (for efficient/comfortable heating & cooling), & the outdoor unit (taking into account the noise it will make). Plan if you'll want one indoor unit, which is probably all you need (in your living area) or whether you want additional units (in the master bed or elsewhere). If you want more than one indoor unit, are you happy with single head systems (which has one outdoor unit per indoor unit), or a multi-head system (which have only one outdoor unit for multiple indoor unit). I believe multi-head systems aren't quite so efficient as single-head systems. When determining which system to choose, to determine the efficiency, look for "COP", the co-efficient of performance. Smaller systems are generally more efficient (as their heat exchangers are larger, relative to their output). Though you don't want to undersize, as the unit will have to work too hard (although the required heat load for your house should be lower, due to the passive solar nature, & good insulation). Inverter models are also more efficient, as these can ramp up & ramp down when required, instead of runing at full power constantly, turning off & on. If you're not keen on the appearance of wall mounted split systems, there's other options for the indoor unit. Including ceiling cassettes, bulkhead units & floor mounted units. Floor units can be particularly efficient for heating, as hot air rises. To reduce the heating you'll require, I'd also consider "zoning" your house a bit better, by installing a door at the end of the hallway (between bed 3 & the fridge). This will reduce the area to be heated when you're heating your living area. Lastly, don't forget about window furnishings. Glass is a VERY poor insulator, even double glazing. So make sure you have good quality curtains, with pelmets. Or choose cellular (honeycomb) blinds, which are very good insulators. Good luck with the build. Re: Install heating/cooling during build or wait and see? 10Jul 24, 2016 1:24 am ddarroch As for AC, you said "ducted reverse cycle split system". I'm no expert, but I don't think you can have a ducted split system, I think it's either "ducted" or "split". Sorry to correct you there but a ducted system is still be a split system if the compressor and outdoor coil is separate to the indoor unit in the ceiling and connected by pipework as opposed to a package unit with everything in the one enclosure/housing. Refer to here https://en.wikipedia.org/wiki/Air_conditioning#Split_systems hope that clears it up Re: Install heating/cooling during build or wait and see? 11Jul 24, 2016 9:26 am Good question justalittlebithippy and great response ddarroch. Just to add from our experience we have a total electric house with induction cooking, heat pump hot water and 5kv PV, no heating or cooling but have prewired for 2 splits. Have been in the house for one summer and nearly one winter and could count on one hand the times it may have been nice to take the chill off but instead put on a jumper. We use fans, high louvre windows and control cross ventilation. Definitely agree that window furnishings help and probably why we have experienced the coolness occasionally as we didn’t want covering on our rear windows cause of not needing privacy, will look into this before next winter. We're in northern nsw for prospective. Good luck! Custom build Northern NSW viewtopic.php?f=31&t=72217 Re: Install heating/cooling during build or wait and see? 12Jul 24, 2016 10:25 am Bels ddarroch As for AC, you said "ducted reverse cycle split system". I'm no expert, but I don't think you can have a ducted split system, I think it's either "ducted" or "split". Sorry to correct you there but a ducted system is still be a split system if the compressor and outdoor coil is separate to the indoor unit in the ceiling and connected by pipework as opposed to a package unit with everything in the one enclosure/housing. Refer to here https://en.wikipedia.org/wiki/Air_conditioning#Split_systems hope that clears it up Thanks for the correction Bels, good to know. You're certainly the expert Come to think of it, the system in my parent's apartment is a ducted split I'm guessing they're often a good option, with the seamless look of a ducted system, but with lower losses due to shorter duct runs? Re: Install heating/cooling during build or wait and see? 13Jul 26, 2016 2:26 pm Thanks everyone I certainly have thought about doing the no gas connection electric only house, and I think that's probably what I will do for my forever house, but I'm just not sure I can justify the extra upfront expense for this house. Unless it would be the same cost and I've just missed something? And yes, will probably be doing a combination of heavy curtains and the honeycomb blinds, and definitely pelmets. The honeycomb blinds do look very interesting, can anyone recommend a good supplier please? The other thing is I'd really love a coonara type wood heater in the main living area because I love the feel of real fire, would I be crazy to just put that in earlier than I was originally planning and see if that negates the need for ducted heating? And one last question, does anyone have any experience with whole house fans vs individual ceiling fans in each room? Cheers Re: Install heating/cooling during build or wait and see? 14Jul 26, 2016 7:04 pm Hi I think that your insulation is pretty low, 1.5 in the ceiling and 2.5 walls is hardly anything. The roof is where you will lose most. Think about putting a lot more up there. Cheers Lorri Re: Install heating/cooling during build or wait and see? 15Jul 26, 2016 9:12 pm That's 5.1 in the ceiling Lorri that was what the gov yourhome website suggested for my area, but happy to hear arguments for more. Re: Install heating/cooling during build or wait and see? 16Jul 26, 2016 9:26 pm ddarroch Come to think of it, the system in my parent's apartment is a ducted split I'm guessing they're often a good option, with the seamless look of a ducted system, but with lower losses due to shorter duct runs? Hey mate, are you comparing a ducted refrigerated system to a ducted gas heating system with possibly addon cooling? You are right to a degree with the duct losses but it's not really an apples to apples comparison. Re: Install heating/cooling during build or wait and see? 17Jul 26, 2016 11:03 pm Hi Justalittlebithippy It might pay to consult a green engineer who can look over your plans and would make recommendations on what you could improve on if you were aiming for a passive house. Re: Install heating/cooling during build or wait and see? 18Jul 27, 2016 1:14 am Lorri Hi I think that your insulation is pretty low, 1.5 in the ceiling and 2.5 walls is hardly anything. The roof is where you will lose most. Think about putting a lot more up there. Haha, think I must be losing it, not that I ever had "it" had it in the first place. I thought 1.5 was pretty low LoL Re: Install heating/cooling during build or wait and see? 19Aug 03, 2016 3:43 pm Lorri Lorri Hi I think that your insulation is pretty low, 1.5 in the ceiling and 2.5 walls is hardly anything. The roof is where you will lose most. Think about putting a lot more up there. Haha, think I must be losing it, not that I ever had "it" had it in the first place. I thought 1.5 was pretty low LoL Haha, if it makes you feel any better I had to go back and double check that I hadn't got it wrong myself Re: Install heating/cooling during build or wait and see? 20Aug 12, 2016 12:55 pm IN victoria reverse cycle heating is more expensive than gas, most homes in vic end up with ducted gas heating, i use 6star brivis with heavily insulated ductwork, and unit is 35 mjs, and gas bills are still quite low in winter. 1 9559 Just to makea point about this, an approach that some people have found sucessful in negotiating these rises down, Is to provide some workings to the builder, specifying… 4 65253 That's a fantastic result! Happy you got it sorted out. cheers Simeon 6 7534 |